The present invention relates generally to magnetic thin film inductors and in particular the present invention relates to magnetic thin film inductors with improved inductance and quality factor at relatively high frequencies.
Inductors used in integrated circuits are typically mounted on a substrate of the integrated circuit. An inductor typically comprises conducting material formed in a straight line or spiral shape with magnetic material positioned in close proximity. This type of inductor is typically used in relatively low frequency applications, about 1 giga hertz (GHz) or less. At about 1 GHz, the magnetic material of the prior art typically reaches ferro-magnetic resonance. Inductors operating near and/or beyond their ferro-magnetic resonance frequencies will have poor inductance performance. In particular, they will have a poor quality factor due to relatively high eddy currents and interference. Moreover, existing inductors generally take up a relatively large amount of space. In wireless communication operations, it is desired to have an inductor that is relatively small and can operate at a frequency above 1 giga hertz. Accordingly, it is desired in the art for an inductor design that can operate at a relatively high frequency with high inductance while taking up a relatively small amount of space.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for an efficient inductor that can operate at relatively high frequencies.
The above-mentioned problems with existing inductors and other problems are addressed by the present invention and will be understood by reading and studying the following specification.
In one embodiment, a magnetic thin film inductor is disclosed. The magnetic thin film inductor includes a plurality of elongated conducting regions and magnetic material. The plurality of elongated conducting regions are positioned parallel with each other and at a selected spaced distance apart from each other. The magnetic material encases the plurality of conducting regions, wherein when currents are applied to the conducting regions, current paths in each of the conducting regions cause the currents to generally flow in the same direction thereby enhancing mutual inductance.
In another embodiment, a magnetic thin film inductor is disclosed that comprises a conducting member having one or more turns and portions of magnetic material. The portions of magnetic material encase the one or more turns of the conducting member. Moreover, each portion of magnetic material encases portions of the one or more turns that conduct current in a substantially uniform direction.
In another embodiment, a magnetic thin film inductor comprises a conductive member and magnetic material. The conductive member is formed into one or more coils. The magnetic material is formed to encase the one or more coils. The magnetic material has a central opening. The one or more coils extend around the central opening. The magnetic material further has a plurality of gaps.
In another embodiment, a method of forming a magnetic thin film inductor is disclosed. The method comprises forming a first layer of magnetic material on a substrate. Forming a layer of conducting material overlaying the first layer of magnetic material. Patterning the conductive layer to form two or more generally parallel conducting members, wherein the two or more conductive members are positioned proximate each other. Forming a second layer of magnetic material overlaying the conductive members and portions of the first layer of magnetic material, wherein the conductive members are encased by the first and second layers of magnetic material.
In another embodiment, a method of forming a magnetic thin film inductor is disclosed. The method comprises forming a first layer of magnetic material on a substrate, forming a layer of conductive material overlaying the first layer of magnetic material and patterning the conductive material to form one or more turns of a conductive member in a predefined shape. Forming a second layer of magnetic material overlaying the one or more turns of the conductive member and the first layer of magnetic material. Removing portions of the first and second layers of magnetic material to form a central opening to the substrate, wherein the first and second layers of magnetic material encase the one or more conducting members that extend around the central opening.
In another embodiment, a method of operating a magnetic thin film inductor in an integrated circuit is disclosed. The method comprises coupling a current to a plurality of conducting members positioned generally parallel with each other and encased by sections of magnetic material, wherein each section of magnetic material encases a plurality of conducting members in which current is flowing in generally the same direction.